1. Field of the Invention
The present invention relates to a portable communication terminal including a cellular phone, personal digital assistants (PDAs), a TV phone for watching Digital Multimedia Broadcasting (DMB) and the like, and more particularly to a joystick apparatus for a portable terminal of which the housing is used as a part of the joystick apparatus.
2. Description of the Related Art
Generally, the term “terminal” refers to a video cassette player, a camera, a portable communication device, a personal computer, a plasma display panel, and the like.
Here, the “communication device” refers to a device which a user can carry and through which the user can perform wireless communication with another user. Such a portable communication device includes a hand held phone, a second generation cellular phone, a digital phone, a personal communication system phone, and PDAs, which are classified into various types according to its appearance. For example, a wireless terminal is classified into a bar-type wireless terminal, a flip-type wireless terminal or a folder-type wireless terminal according to their appearance. The bar-type wireless terminal refers to a terminal having single bar-type housing. The flip-type wireless terminal refers to a terminal in which a flip or a cover is rotatably connected by a hinge device to a bar-type housing. The folder-type wireless terminal refers to a terminal in which a folder is rotatably connected by a hinge device to single bar-type housing and folded. A conventional terminal is essentially provided with an antenna, a data input unit, a data output unit, and a data transceiver-unit. The data input unit generally includes key buttons which a user can push with his/her fingers to input data. Moreover, a touch pad or a touch screen may be used as the data input unit.
Further, the user can write a message using the key buttons of a portable terminal and send it to another user.
The key buttons include a plurality of key arrays to input data. These key buttons include a send key button used to start the communication, a cancel key button, a clear key, a power key, an end key, numeral keys, character keys, function keys, etc.
As shown in FIG. 1, the key input unit of the portable communication terminal has a keypad 1a and 4-way control keys 1b arranged on a front surface thereof, and a plurality of side keys (not shown) assisting the function of the keypad 1a and playing the role of function keys.
The key input unit is provided with the 4-way control keys 1b to control a movement direction of an activated cursor and to move the cursor in one direction, left, right, upward, and downward directions.
Recently, multifunctional portable communication terminals have come onto the market, to which a MP3 player function, a moving picture player function, and a game function have been added.
The conventional portable communication terminal's key buttons provide adequate means for controlling communication functions but they are inefficient in a case when a user is about to play the game. Using the conventional portable communication terminal, the user inputs direction information into the game program using the keypad 1a and the 4-way control keys 1b, thereby causing the efficiency of the game to degrade due to awkwardness of using the keys.
As shown in FIG. 2, an easily operated joystick unit 2 has been provided to eliminate the problem as described above.
The conventional joystick unit 2 for the portable terminal has been implemented as a small joystick on an upper portion of the keypad of the portable terminal, or has been connected to the portable terminal by means of a separate connector.
However, the conventional joystick unit embedded in the portable terminal is too small, which makes it is difficult to use. In addition, it is inconvenient for a user to carry the conventional joystick unit connected to the portable terminal by a separate connector.